The present invention relates to a capo for a stringed instrument, in particular a guitar, banjo or similar such instrument.
A capo, sometimes variously termed a capodastro, capodaster, capo tasto or cedilla, is a device well-known and used by players of stringed instruments and in particular guitar and banjo players. A capo can be used with a stringed instrument, for example a guitar or banjo, which has a neck and a set of strings extending along the length of the neck. The neck comprises a fingerboard portion adjacent to the strings and a back. The fingerboard includes a number of fret bars which protrude slightly from the fingerboard/neck surface and extend laterally across the neck. The capo, when applied, serves to hold the strings against the fingerboard provided along the neck, and in particular against one of the number of fret bars disposed along the length of the fingerboard and which extend from the fingerboard, to reduce the effective length of the strings and therefore adjust the pitch produced by the strings.
When a capo is in use on an instrument neck a string engaging portion or arm of the capo is arranged to press the strings against the surface of the fingerboard to sandwich the strings against the fret bars and/or fingerboard. In order to press the string engaging portion against the fingerboard the capo is required, and includes: suitable means for it, to be clamped to the neck. In a number of previous capo designs the clamping of the capo to the neck has been provided through the use of relatively cumbersome clamping mechanisms utilising screw mechanism, toggle levers and other means which are difficult to handle and/or time consuming to attach. In particular, the constructions of previous capos have generally been such that the acts of attaching one to an instrument neck, removing it, or moving its position have undesirably required the use of two hands.
With prior designs of capo including levers or screw mechanisms to apply the clamping load a degree of mechanical advantage is used to apply the clamping load and press the capo against the strings and towards the fingerboard. Whilst the use of such mechanical advantage makes applying sufficient clamping force easier it can cause problems. In particular with such arrangements, due to the mechanical advantage, it is relatively easy to, unintentionally and accidentally, apply too great a clamping force. This can lead to overstressing of the strings, especially when the capo is used close to a fret bar on the instrument, which can damage the strings, alter the tuning and/or in the extreme damage the instrument neck. The clamping force and pressure applied with such capos can also not be directly sensed or felt by the player. The player therefore loses a degree of xe2x80x98feelxe2x80x99 which, as would be understood, is undesirable. A yet further problem with some of these designs is that the clamping arrangements tend, to some extent, to be specific or require substantial adjustment, to particular instruments and the profile and sizes of neck of the instrument. It is therefore often difficult, time consuming, and cumbersome for such capos to be used on different instruments, different sized necks and/or on a single instrument which has a neck having a cross section which varies substantially along its length.
There are numerous examples of such capo designs including such clamping mechanisms. In particular examples of such designs are proposed and described in the following patents: U.S. Pat. Nos. 5,492,045; 4,149,443; and 5,792,969.
In other prior capo designs spring mechanisms (generally torsion springs) are used to provide the clamping force. Examples of such capos are described in U.S. Pat. Nos. 4,143,576 and 4,583,440. With these designs the string engaging arm is pivotally attached at one end to a clamping arm. In use the capo is fitted to the instrument neck with the string engaging arm abutting against the strings and press the strings toward the fingerboard whilst the clamping arm abuts and bears against the opposite rear surface of the neck. A torsion spring is provided within the pivotal mounting to urge the two arms together, with the strings and neck of the instrument sandwiched therebetween, and provide the clamping force.
As described in the prior patents such capo designs are easier and quicker to apply and can be fitted by the player one handed. There is however still the real possibility that the capo may overstress the strings and/or instrument since the torsion spring may be too strong for a particular instrument or position on the instrument neck. The clamping force provided by the spring will also vary depending upon how wide the arms are opened in order to accommodate the neck and consequently the clamping force may vary when the capo is used on different sizes of instrument necks. Furthermore with such capos the player has no control over the clamping force applied, with the clamping force being determined by the stiffness of the spring. Such lack of control over the clamping force and pressure applied is clearly undesirable for the musician. In addition if the spring is too stiff for a particular instrument then over stressing can occur. The position of the capo arms is also not locked or secured, with the capo simply relying on the resilience of the spring to hold it in place.
It is therefore desirable to provide an improved capo which addresses the above described problems by providing a capo which is simple and easy to apply and which will not overstress the strings or neck of the instrument and/or which offers improvements generally.
According to the present invention there is provided a capo as described in the accompanying claims.
In an embodiment of the invention there is provided a capo for use with a stringed instrument having a plurality of strings and a neck. The neck comprises a fingerboard and a back. The capo comprises a string engaging arm, a clamping arm and a pivotal connection to pivotally interconnect the two arms. The string engaging arm is adapted to extend across the fingerboard above the strings and in use press against the strings. The clamping arm is adapted, in use, to extend across and engage the back of the neck. The pivotal connection pivotally interconnects the clamping arm to the string engaging arm at a position along said arms that is arranged, in use, to be adjacent said neck such that the arms can be pivoted relative to each other in order to, in use, fit and clamp the strings and neck between said arms. Preferably the pivotal connection is disposed, in use, generally towards one side of the neck. The pivotal connection includes a releasable locking means which is operable to selectively lock and unlock the pivotal connection and the relative pivotal movement of the clamping arm and string engaging arm at least in a particular direction.
Such a capo of this embodiment of the invention addresses the above described problems with the locking mechanism providing a means for locking the position of the arms and the capo in the position set by the player. The clamping force applied by the capo can therefore be set by the player applying the required force to close the capo on the neck of the instrument with this clamping force then being maintained by the locking means which prevents the arms and capo from opening.
Preferably the locking means is operable to selectively lock and unlock the pivotal connection and relative pivotal movement of the clamping arm and string engaging arm away from each other and the neck of the instrument and so prevent opening of the capo when locked. Furthermore the releasable locking means may advantageously be biassed so that the pivotal connection is normally locked to prevent opening of the capo.
In this way the capo can then be closed on the neck and the required clamping force applied with the locking means already engaged. There is therefore no need to separately actuate the locking means as the required clamping force is applied so making the fitting of the capo even easier.